From the outside, clould mining is indistinguishable to a any kind of hands-off turn key investment. You pay money to a person, group or company; hereafter referred to as a "party." This group will use the money ostensibly to earn more money from it. In cloud mining you pay money and the party will ostensibly put money into buying new equipment and electricity for the existing mining equipment.

You just don't know for sure until people have already been scammed, or missed your opportunity. Sometimes people make money early on and then show that as proof. After that, the next group to get in get burned.